Experimental Analysis of Repaired Masonry Elements with Flax-FRCM and PBO-FRCM Composites Subjected to Axial Bending Loads

Oscar Cevallos,Rosamaria Codispoti,Renato Olivito

doi:10.3390/fib3040491

Oscar Cevallos, Rosamaria Codispoti + Show 1 more

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https://doi.org/10.3390/fib3040491

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Abstract

In the construction industry, the use of natural fabrics as a reinforcement for cement-based composites has shown great potential. The use of these sustainable composites to provide strengthening or repair old masonry structures that exhibit structural problems mainly due to a poor tensile strength of the mortar/brick joints is revealed to be a promising area of research. One of the most significant load conditions affecting the mechanical response of masonry structures occurs when axial bending loads are applied on the resistant cross-section. In this study, three different types of masonry elements were built using clay bricks and a lime-based mortar. After 28 days, the samples were subjected to concentric and eccentric compressive loads. In order to produce significant bending effects, the compressive loads were applied with large eccentricity, and a sudden failure characterized the behavior of the unreinforced masonry (URM) elements. The tested masonry specimens were repaired using fabric-reinforced cementitious matrix (FRCM) composites produced using bi-directional flax and polyparaphenylene benzobisoxazole (PBO) fabrics. The mechanical behavior of the URM and repaired samples was compared in terms of load-displacement and moment-curvature responses. Furthermore, the results achieved using flax-FRCM composites were compared with those of using PBO-FRCM composites.

Highlights

Composites reinforced with natural fibers have attracted the interest of scientists over the past several decades [1,2,3,4,5]
And 5, the unreinforced masonry (URM) specimens subjected to axial bending loads were repaired and strengthened with the Fabric-reinforced cementitious matrix (FRCM) composites. Considering these specimens, the FRCM composites prevented the failure when openings in the mortar joints were manifested by the tensile stresses during the tests
The mechanical response in terms of load capacity and deformability of URM elements subjected to eccentric loads was compared against results obtained with masonry samples repaired using either flax- or polyparaphenylene benzobisoxazole (PBO)-FRCM composites

Summary

Introduction

Composites reinforced with natural fibers have attracted the interest of scientists over the past several decades [1,2,3,4,5]. From an environmental point of view, the use of natural fabrics to produce FRCM composites could significantly help in solving several problems of sustainability in the construction industry. For this reason, researchers have directed their attention toward the study of new materials based on natural fibers and renewable resources. Mortar-based composites reinforced with basalt fabrics and steel textiles have attracted the interest of scientists in recent years [20,21,22] In these studies, the results demonstrate the promising mechanical properties of the systems. Several studies have been conducted to demonstrate the efficacy of FRCM composites to strengthen concrete and masonry structures, in which fabrics of traditional or synthetic fibers such as glass, carbon, polyparaphenylene benzobisoxazole (PBO), and aramid have been used [23,24,25]

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